Process for obtaining aluminum.



PARKER c. MoILI-IINEY, 0F can'er NECK, NEW YORK.

PROCESS .FOR OBTAINING ALUMINUM.

No Drawing,

To all whom, it may concern:

Be it known that I, PARKER C. Mc- IIJIINEY, a citizen of the United States, and a resident of Great Neck, -l\'orth Hem stead, Nassau county, State of New Yor have invented certain new and useful Improvements in Processes for Obtaining Aluminum, of which the following is a specification. s

My invention relates to improvements 1n processes for-obtaining metallic almninmn from its ores, and inone form it comprehends also the obtaining in a profitable manner of a valuable by-product. 1

Aluminum has been extracted heretofore fromthe oxid, alumina (made from the ore by a separate operation), by dissolving the oxid in a bath of molten fluorids and passing an electric current through the resulting liquid, whereupon metallic aluminum and oxygen are separated'and aluminum is obtained in the metallic form.

In my process in its preferred form, I add to the bath of molten fluorids the lluorid of aluminum instead, of the ovid. and at the same time act upon the fiuorid with steam, ivherchy there is a ready reaction between the aluminum fluorid and the steam with the production of alumina, z. 6., the oxid of aluminum, and hydrofluoric 301d which acid is carrlcd away together with any excess ofwater vapor and condensed for further use, Wlllle the alunnna or 03nd of aluminum remains dissolved in the bath of molten fluorids to be decomposed as heretofore for the recovery of the metallic alu- 1n1nmn.

ara-ted from the solution. containing the aluminum, and the solution neutralized as by adding clay, bauxite, etc. whereby the remaining silica is precipitated and a solution of aluminum fiuorid obtained. The potassium silico-fluorid is heated to a red heat with calcium sulfate, to. produce potassium sulfate which may be leached out so, that the potash is obtained-in suitable Specification of Letters Patent.

Patent-ed J an. 6,1914.

I Application filed August 18, 1913, Serial No- 785,382.

form for fertilizer, etc., in a manner Well understood by those skilled in the art. Instead of using orthocla-se, a pulverized mineral such as clay may be treated with aqueous hydrofluoric acid until the solution is neutral, to produce a solution of aluminum ,fluorid which is then separated from the silica and other deleterious impurities.

' From these solutions of aluminum fiuorid I.

then separate the aluminum fluorid by evaporation, refrigeration, or by other suitable means, and so obtain a solid aluminum fluorid. This solid aluminum fluorid (which may or may not contain water of crystal-- lization) I then add directly to the molten bath. The bath preferably consists of a mixture of aluminumfluorid and cryolite,

the sodium in the cryolite beingmore electropositi ve thanraluminum; The aluminum fluori'd is fed substantially continuously into a closed compartmentcovering a part of the molten bath. A suitable steam jet is directed into this closed compartment near the surface of the'bath and the Water in the form of steam or water vapor is allowed toact upon the molten fluorids or the alnminmn fluorid as it is entering the bath. The water reacts very readily with the alumin'un'r fluorid on account of the excess of the aluminum fluorid constantly present,

for no particular portion of aluminum fluorid need be completely converted into oxid by the steam altliough the supply of steam must be such as to convert into oxid in a giycn time the amount of aluminum fiuorid 1ntroduced in the same time.

The presence in the bath. consisting of molten fluorids of a considerable amount of used the amount of water which is used would necessarily be greater than if the hydra-ted; aluminum fluorid contain suflicient water it may be possible to'omit the separate application of the steam. The closed compartment )is provided with an exit for the hydrofluoric acid produced by the reac-* tion' of the aluminum fluorid with the steam which injected into or upon the molten .drated crystals were us'ed, While-it thehy a 

